Memory for speech and speech for memory

An experiment on measuring awareness of stuttering in individuals with Down syndrome

BACKGROUND

Awareness of stuttering is likely to depend upon the development of the metalinguistic skill to discriminate between fluent speech and stuttering and the ability to identify one's own speech as fluent or stuttered. Presently, little is known about these abilities in individuals with Down syndrome (DS).

PURPOSE

This study investigates whether individuals with DS and typically developing (TD) children who stutter and who do not stutter differ in their ability to discriminate between fluent speech and stuttering. The second purpose of this study is to discover if this ability is correlated with their self-identification ability.

METHOD

An experiment to investigate awareness with tasks for discrimination of stuttering and self-identification was developed. It was administered to 28 individuals (7-19 years) with DS, 17 of them stutter and 11 do not, and 20 TD children (3-10 years), 8 of them stutter and 12 do not. Skills to discriminate stuttering were compared between these groups and correlated with self-identification within these groups. The influence of stuttering severity and developmental/chronological age on their ability to discriminate was also investigated.

RESULTS

The ability to discriminate does not differ significantly between the DS and TD group, but is highly influenced by developmental age. This ability correlates with self-identification but only for the TD individuals who speak fluently.

CONCLUSION

The ability to discriminate matures around the age of 7 and conscious awareness may rely on this ability. Differences between the present findings and earlier studies suggest that differentiation in levels and types of awareness is warranted.

Speech Perception Skills of Children With Speech Sound Disorders: A Systematic Review and Meta-Analysis

Purpose The aim of this study was to conduct a systematic review and meta-analysis to investigate whether preschool- and early school-age children with speech sound disorders (SSDs) have difficulties with speech perception. Method Systematic searching of 8 electronic databases identified 73 eligible studies across 71 articles examining the speech perception skills of children with SSDs. The findings and methodological characteristics of each study were reviewed, and the reporting of methodological information in each article was rated. A meta-analysis was conducted with studies that used the most common type of speech perception assessment task-lexical and/or phonetic judgment tasks. Results Across 60 of 73 studies, some or all children with SSDs were reported to have difficulties with speech perception. The meta-analysis showed a significant difference between children with SSDs and children with typically developing speech on lexical and/or phonetic judgment tasks. Conclusion Results from the meta-analysis demonstrate that children with SSDs have difficulties with speech perception. This appears to be the case for some but not all children with SSDs. The findings from this systematic review and meta-analysis also provide insight into the complex range of methodological issues involved in the study of speech perception in children with SSDs and the need for further research. Supplemental Material https://doi.org/10.23641/asha.9808361.

Perception of Sibilants by Preschool Children With Overt and Covert Sound Contrasts

Purpose This study explores the role of overt and covert contrasts in speech perception by children with speech sound disorder (SSD). Method Three groups of preschool-aged children (typically developing speech and language [TD], SSD with /s/~/ʃ/ contrast [SSD-contrast], and SSD with /s/~/ʃ/ collapse [SSD-collapse]) completed an identification task targeting /s/~/ʃ/ minimal pairs. The stimuli were produced by 3 sets of talkers: children with TD, children with SSD, and the participant himself/herself. We conducted a univariate general linear model to investigate differences in perception of tokens produced by different speakers and differences in perception between the groups of listeners. Results The TD and SSD-contrast groups performed similarly when perceiving tokens produced by themselves or other children. The SSD-collapse group perceived all speakers more poorly than the other 2 groups of children, performing at chance for perception of their own speech. Children who produced a covert contrast did not perceive their own speech more accurately than children who produced no identifiable acoustic contrast. Conclusion Preschool-aged children have not yet developed adultlike phonological representations. Collapsing phoneme production, even with a covert contrast, may indicate poor perception of the collapsed phonemes.

Self-Judgments of Word Production Accuracy in Acquired Apraxia of Speech

PURPOSE

The ability to recognize one's own speech errors has long been considered a clinical feature of acquired apraxia of speech (AOS) despite limited empirical data supporting this notion. This study was designed to (a) investigate the ability of speakers with AOS to self-judge the accuracy of their own word productions and (b) examine the test-retest stability of a measure to quantify the self-judgments of speakers with AOS.

METHOD

Twenty-four speakers with AOS and aphasia repeated mono- and multisyllabic words. After each word, they indicated whether their production was correct or incorrect. This procedure was repeated 1 week later to examine performance stability.

RESULTS

Percentage of incorrect word productions was stable for the group across times. Accuracy of judgments ranged from 64% to 100% at Time 1 and from 56% to 100% at Time 2. Inaccurate judgments of error productions (false positives) occurred much more frequently than inaccurate judgments of correct productions (false negatives).

CONCLUSIONS

Error production was remarkably stable in our participants. As a group, the participants failed to detect almost one third of words produced erroneously. However, accuracy and stability of judgments over sampling times varied across participants. Findings suggest that error awareness might be a worthwhile target for treatment in some individuals with AOS.

Children's perception of their synthetically corrected speech production

We explore children's perception of their own speech - in its online form, in its recorded form, and in synthetically modified forms. Children with phonological disorder (PD) and children with typical speech and language development (TD) performed tasks of evaluating accuracy of the different types of speech stimuli, either immediately after having produced the utterance or after a delay. In addition, they performed a task designed to assess their ability to detect synthetic modification. Both groups showed high performance in tasks involving evaluation of other children's speech, whereas in tasks of evaluating one's own speech, the children with PD were less accurate than their TD peers. The children with PD were less sensitive to misproductions in immediate conjunction with their production of an utterance, and more accurate after a delay. Within-category modification often passed undetected, indicating a satisfactory quality of the generated speech. Potential clinical benefits of using corrective re-synthesis are discussed.

Children's recognition of their own recorded voice: influence of age and phonological impairment

Children with phonological impairment (PI) often have difficulties perceiving insufficiencies in their own speech. The use of recordings has been suggested as a way of directing the child's attention toward his/her own speech, despite a lack of evidence that children actually recognize their recorded voice as their own. We present two studies of children's self-voice identification, one exploring developmental aspects, and one exploring potential effects of having a PI. The results indicate that children from 4 to 8 years recognize their recorded voice well (around 80% accuracy), regardless of whether they have a PI or not. A subtle change in this ability from 4 to 8 years is observed that could be linked to a development in short-term memory. Clinically, one can indeed expect an advantage of using recordings in therapy; this could constitute an intermediate step toward the more challenging task of online self-monitoring.

Embodied cognition for autonomous interactive robots

In the past, notions of embodiment have been applied to robotics mainly in the realm of very simple robots, and supporting low-level mechanisms such as dynamics and navigation. In contrast, most human-like, interactive, and socially adept robotic systems turn away from embodiment and use amodal, symbolic, and modular approaches to cognition and interaction. At the same time, recent research in Embodied Cognition (EC) is spanning an increasing number of complex cognitive processes, including language, nonverbal communication, learning, and social behavior. This article suggests adopting a modern EC approach for autonomous robots interacting with humans. In particular, we present three core principles from EC that may be applicable to such robots: (a) modal perceptual representation, (b) action/perception and action/cognition integration, and (c) a simulation-based model of top-down perceptual biasing. We describe a computational framework based on these principles, and its implementation on two physical robots. This could provide a new paradigm for embodied human-robot interaction based on recent psychological and neurological findings.

Predictors of verbal working memory in children with cerebral palsy

The goal of the present study was to examine the precursors of verbal working memory in 52 children with cerebral palsy with varying degrees of speech impairments in the first grade of special education. Following Baddeley's model of working memory, children's verbal working memory was measured by means of a forced-recognition task. As precursors of verbal working memory, measures of intelligence, speech rate, speech intelligibility, auditory perception, and phonological awareness were also administered. Correlations were computed between all measures followed by Structural Equation Modeling analyses with speech rate and speech intelligibility being identified as a single factor 'speech'. The results revealed that verbal working memory was mostly predicted by intelligence, auditory perception and speech ability. It was also found that children with cerebral palsy with additional intellectual and speech impairments were at risk for limited verbal working memory spans.

Working memory involvement in stuttering: exploring the evidence and research implications

Several studies of utterance planning and attention processes in stuttering have raised the prospect of working memory involvement in the disorder. In this paper, potential connections between stuttering and two elements of Baddeley's [Baddeley, A. D. (2003). Working memory: Looking back and looking forward. Neuroscience, 4, 829-839] working memory model, phonological memory and central executive, are posited. Empirical evidence is drawn from studies on phonological memory and dual-task performance among children and adults who stutter to examine support for the posited connections. Implications for research to examine working memory as one of the psycholinguistic bases of stuttering are presented.

EDUCATIONAL OBJECTIVES

The reader will learn about and be able to: (1) appraise potential relationships between working memory and stuttering; (2) evaluate empirical evidence that suggests the possibility of working memory involvement in stuttering; and (3) identify research directions to explore the role of working memory in stuttering.

What is the relationship between phonological short-term memory and speech processing?

Traditionally, models of speech comprehension and production do not depend on concepts and processes from the phonological short-term memory (pSTM) literature. Likewise, in working memory research, pSTM is considered to be a language-independent system that facilitates language acquisition rather than speech processing per se. We discuss couplings between pSTM, speech perception and speech production, and we propose that pSTM arises from the cycling of information between two phonological buffers, one involved in speech perception and one in speech production. We discuss the specific role of these processes in speech processing, and argue that models of speech perception and production, and our understanding of their neural bases, will benefit from incorporating them.

Perceiving imitatible stimuli: consequences of isomorphism between input and output

For more than a century, psychologists have been intrigued by the idea that mental representations of perceived human actions are closely connected with mental representations of performing those same actions. In this article, connections between input and output representations are considered in terms of the potential for imitation. A broad range of evidence suggests that, for imitatible stimuli, input and output representations are isomorphic to one another, allowing mutual influence between perception and motoric planning that is rapid, effortless, and possibly obligatory. Thus, the cognitive consequences of imitatibility may underlie such diverse phenomena as phoneme perception; imitation in neonates; echoic memory; stimulus-response compatibility; conduction aphasia; maintenance rehearsal; and a variety of developmental and social activities such as language acquisition, social learning, empathy, and monitoring one's own behavior.

The young child's awareness of stuttering-like disfluency

The emergence of awareness of stuttering has been an important factor in theoretical and clinical considerations for early childhood stuttering. The present research program is aimed at studying the development of awareness of stuttering-like disfluency in normally fluent preschool and first-grade children using responses to video speech samples. A total of 79 children in five different age groups were asked to discriminate between the speech (fluent and disfluent) of two puppets, identify with the one who speaks like them, and evaluate the disfluent and fluent speech of the puppets. It was found that from age 3, children show evidence of awareness of the disfluency used in the study, but most children reached full awareness at age 5. Also, negative evaluation of disfluent speech is observed from age 4. Theoretical and clinical implications are discussed.

The case for sensorimotor coding in working memory

The highly influential Baddeley and Hitch model of working memory (Baddeley & Hitch, 1974; see also Baddeley, 1986) posited analogical forms of representation that can be broadly characterized as sensorimotor, both for verbal and for visuospatial material. However, difficulties with the model of verbal working memory in particular have led investigators to develop alternative models that avoid appealing either to sensory coding or to motoric coding, or to both. This paper examines the evidence for sensorimotor coding in working memory, including evidence from neuropsychology and from sign language research, as well as from standard working memory paradigms, and concludes that only a sensorimotor model can accommodate the broad range of effects that characterize verbal working memory. In addition, several findings that have been considered to speak against sensorimotor involvement are reexamined and are argued to be in fact compatible with sensorimotor coding. These conclusions have broad implications, in that they support the emerging theoretical viewpoint of embodied cognition.

The development of phonological skills

In this paper we consider the nature and consequences of the development of phonological skills in children. We begin with evidence for developmental refinements in phonological processes. These developments, in turn, affect a variety of other skills. We consider two particular examples: the relationship between the development of speech skills and verbal short-term memory and the development of children's phonological awareness. The development of phonological awareness is related to the acquisition of literacy, which, in turn, brings about further refinements in phonological skills.

Depth of phonological recoding in short-term memory

In testing the hypothesis that surface phonetic form is included in short-term memory (STM) representation, the tone sandhi phenomenon in Mandarin Chinese was exploited, and, as a prerequisite, the hypothesis that tonal similarity affects STM of verbal material in a tone language was also tested. In Experiment 1, subjects recalled visually presented sequences of seven monosyllabic Chinese morphemes having either the same tone or different tones. More errors were made on the monotonal sequences than on the multitonal sequences, confirming the effect of tonal similarity on STM. In Experiment 2, subjects recalled visually presented sequences of disyllabic nonsense words. The sequences were designed in such a way that half of them were subject to the tone sandhi rule in Mandarin Chinese, whereas the other half were not. The consequence of applying the tone sandhi rule, as designed, was to make all the first characters in the sequences identical in pronunciation, thus creating potential phonological confusion. More errors, indeed, occurred on the sequences subject to the tone sandhi rule than on those not subject to it, indicating the existence of a surface phonetic representation in STM. The findings in this study provide further insight into the phonological mechanism of STM. Different accounts for this mechanism are also discussed in the light of the new findings.

A second look at tests of speech-sound discrimination

This study is an extension of an earlier study conducted by Bountress and Laderberg (1981), which compared the performances of a group of children on two tests of speech-sound discrimination, the Wepman test and Goldman-Fristoe-Woodcock test. The present study consisted of two treatments: The dual administration of the Boston University Speech Sound Discrimination Test and Wepman, and the Boston and Goldman-Fristoe-Woodcock to two groups of 25 children. An analysis of the results of the two treatments indicated that, as was the case in Bountress and Laderberg's original research comparing the Wepman and Goldman-Fristoe-Woodcock, neither the Boston or Wepman nor the Boston or Goldman-Fristoe-Woodcock comparisons provided evidence that they are comparable measures of speech-sound discrimination. The results of both studies are analyzed, and implications are discussed.

A comparison of two tests of speech-sound discrimination

This study was conducted for the purpose of comparing two tests of speech-sound discrimination which are commonly used by speech-language clinicians, the Wepman and Goldman-Fristoe-Woodcock. In particular, it was the purpose of the study to ascertain whether the tests were significantly comparable measures of speech-sound discrimination. Both tests were administered to a group of 22 5-yr-old subjects who did not present speech, language, auditory, neurological, learning, or behavioral disorders or obvious dialectal variations. An analysis of the results indicated that the Wepman and Goldman-Fristoe-Woodcock tests were not comparable measures of speech-sound discrimination and that the Goldman-Fristoe-Woodcock was a harsher measure of that skill. Implications of these results are discussed.